/*! Copyright (c) 2009 Brandon Aaron (http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * Thanks to: http://adomas.org/javascript-mouse-wheel/ for some pointers.
 * Thanks to: Mathias Bank(http://www.mathias-bank.de) for a scope bug fix.
 *
 * Version: 3.0.2
 * 
 * Requires: 1.2.2+
 */

(function($) {

	var types = [ 'DOMMouseScroll', 'mousewheel' ];

	$.event.special.mousewheel = {
		setup: function() {
			if (this.addEventListener)
				for ( var i = types.length; i;)
					this.addEventListener(types[--i], handler, false);
			else this.onmousewheel = handler;
		},

		teardown: function() {
			if (this.removeEventListener)
				for ( var i = types.length; i;)
					this.removeEventListener(types[--i], handler, false);
			else this.onmousewheel = null;
		}
	};

	$.fn.extend( {
		mousewheel: function(fn) {
			return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
		},

		unmousewheel: function(fn) {
			return this.unbind("mousewheel", fn);
		}
	});

	function handler(event) {
		var args = [].slice.call(arguments, 1), delta = 0, returnValue = true;

		event = $.event.fix(event || window.event);
		event.type = "mousewheel";

		if (event.wheelDelta) delta = event.wheelDelta / 120;
		if (event.detail) delta = -event.detail / 3;

		// Add events and delta to the front of the arguments
		args.unshift(event, delta);

		return $.event.handle.apply(this, args);
	}

})(jQuery);